کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
10956346 1098838 2011 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Stage-specific regulation of juvenile hormone biosynthesis by ecdysteroid in Bombyx mori
موضوعات مرتبط
علوم زیستی و بیوفناوری بیوشیمی، ژنتیک و زیست شناسی مولکولی بیولوژی سلول
پیش نمایش صفحه اول مقاله
Stage-specific regulation of juvenile hormone biosynthesis by ecdysteroid in Bombyx mori
چکیده انگلیسی
In the penultimate (4th) instar larvae of Bombyx mori, juvenile hormone (JH) synthesis by corpora allata (CA) fluctuates. When diet containing 20-hydroxyecdysone (20E) was fed, JH synthetic activity of the CA was first stimulated as the ecdysteroid titer increased, then suppressed slightly by the higher molting concentration of ecdysteroids (>250 ng/ml). The overall JH biosynthetic activity was modulated by the expression of JH biosynthetic enzymes in the CA: primarily JH acid O-methyltransferase (JHAMT), isopentenyl diphosphate isomerase, and farnesyl diphosphate synthase 1. After the last (5th) larval ecdysis, the artificially increased high ecdysteroid level due to the 20E diet activated JH synthesis by the CA, which required intact nervous connections with the brain. A factor(s) from the 20E-activated brain controls mainly JHAMT and HMG Co-A reductase expression to stimulate the JH synthesis. In the normal last instar larvae, the ecdysteroid titer declines so that these activation mechanisms are absent; therefore the decline of the ecdysteroid titer after the final larval ecdysis is one of the factors which induces the cessation of the JH synthesis by CA.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Molecular and Cellular Endocrinology - Volume 335, Issue 2, 30 March 2011, Pages 204-210
نویسندگان
, , , ,